我有以下代码定义了我想在我的多目标优化问题中使用的两个约束,model1
model2
并且model3
之前已经可以验证工作。
restrictions <- function (var) {
x <- var[1]; y <- var[2]
restrictions <- logical(2)
restrictions[1] <- (predict(get(model1), data.frame(x, y), type = "response") < 500)
restrictions[2] <- (predict(get(model1), data.frame(x, y), type = "response") > 0)
return (restrictions);
}
在以下代码中构建遗传算法多目标函数:
fn <- function (var) {
x <- var[1]; y <- var[2]
f <- numeric(3)
f[1] <- predict(get(model1), data.frame(x, y), type = "response")
f[2] <- predict(get(model2), data.frame(x, y), type = "response")
f[3] <- predict(get(model3), data.frame(x, y), type = "response")
return (f);
}
最后是使用 mco 库的优化过程
library (mco)
optimum <- mco::nsga2 (fn = fn, idim = 2, odim=3,
constraints = restrictions, cdim = 2,
generations = 100,
popsize= 40,
cprob = 0.5,
cdist = 20,
mprob = 0.5,
mdist = 20,
lower.bounds = c(-80, 50),
upper.bounds = c(-70, 60)
)
主要问题是解决方案不遵守指定的约束。对此有什么想法吗?